Oracle’s monster batch of security updates expected Tuesday will include a fix for a serious misconfiguration issue in its E-Business Suite product that can give hackers access to databases full of sensitive business records.

Renowned database security expert David Litchfield discovered the issue last year on a client’s system and at first he thought it was a backdoor left behind by an attacker.

“On investigation, it turns out the ‘backdoor’ is part of a seeded installation!” he said Monday on Twitter. “I was flabbergasted. Still am.”

In a pre-announcement about its quarterly Critical Patch Update expected today, Oracle said that 10 vulnerabilities will be fixed in E-Business Suite, six of which can be exploited remotely without authentication.

The highest score for the E-Business Suite vulnerabilities that will be patched is 6.4 in the Common Vulnerability Scoring System (CVSS), according to the company. That doesn’t sound too bad, considering that the CVSS scale goes to 10.

However, the flaw discovered by Litchfield is quite serious since, according to the researcher, it allows attackers to execute arbitrary SQL commands as SYS, the highest privileged account in the database. That’s possible because E-Business Suite grants INDEX privileges by default to the PUBLIC role on the DUAL database table, which is owned by SYS.

If attackers can execute arbitrary SQL commands as SYS, they can read everything in the database, including the sensitive business records stored by the customer relationship management (CRM) applications that are part of E-Business Suite.

The Oracle Critical Patch Update for January will contain a total of 167 security fixes for vulnerabilities in hundreds of Oracle products and product versions.

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